The B-2A, at 46.7 percent, has the lowest mission-capable rate in the Air Force fleet. (Air Force)

The RQ-4 Global Hawk, which has been targeted for retirement, saw one of the biggest jumps in mission-capable rates, to 74.1 percent. (Alan Radecki/Northrop Grumman)

The repercussions of budget cuts, aging and long service in Iraq and Afghanistan are reflected in the most recent mission-capable rates of the Air Force fleet: grounded trainers and the important B-2A Spirit least ready for flight of all.

Overall, the Air Force saw only a slight drop in the availability of all of its aircraft — to 77.8 percent in 2013, down from 77.9 percent in 2012, according to recent statistics released by the Air Force.

The declines are “not anything like they were during Desert Storm. Everything has just declined a bit with the age of the aircraft,’’ said Rebecca Grant, an analyst with IRIS Research. “We’ve set a new normal for those rates given the age of the aircraft fleet.”

The Air Force’s most available aircraft were in its executive transport fleet, with the C-37A the highest overall at 96.9 percent and Air Force One, the VC-25A, at about 92 percent. The drone fleet, specifically the MC-1B Predator and MQ-9 Reaper, were both highly capable at 93.4 percent and 91.1 percent, respectively.

The B-2A, at 46.7 percent, was least capable.

For bombers, older is better

In the Air Force’s nuclear-capable bomber fleet, the numbers show that money and youth don’t translate to a more ready force.

The venerable, ancient B-52 fleet flew at a capable rate of 75.3 percent in 2013.While it was a drop of three percentage points from the year before, it is still far and away the highest rate of the Air Force’s bombers, even at an average age of almost 52 years.

The fleet is also in the middle of upgrades, most recently including the initial 1760 Internal Weapons Bay Upgrade. The upgrade will increase the B-52’s internal storage to up to eight advanced Joint Direct Attack Munitions, in addition to the 12 that can already be carried on weapons pylons on the plane’s wings. The upgrade is based on rewiring the B-52’s launcher into a Common Rotary Launcher to let the plane’s targeting and firing systems communicate with newer weapons, according to the Air Force.

Additionally, the B-52 is receiving a new radar system and new computers, data links, satellite terminals and other weapons systems. It goes in for depot maintenance every 48 to 51 months — among the efforts to keep the jets flying.

“As the fleet ages, corrosion control and prevention has become a challenge,” said Senior Master Sgt. Virgil Tims with the B-52 weapons systems team at Air Force Global Strike Command. “We recently revamped our corrosion control and inspection procedures to prevent, identify, treat and repair damage caused by corrosion, which helps extend the aircraft’s service life.”

The B-2, however, has seen its mission-capable rate drop to the lowest in recent memory: 46.7 percent in 2013, down 8 percentage points from 2010. Air Force and contractor officials are revamping the maintenance process for the B-2 as a way to keep more jets available for the service.

One or two jets grounded for maintenance can have a large impact on the 20-jet fleet, Grant said.

Northrop Grumman is planning to demonstrate a new depot system for the bomber next year, in which the B-2 would have a tune-up every five years and a complete overhaul every 10, as opposed to the current system where a B-2 gets a complete overhaul every seven years. The change would give the Air Force access to one more bomber at a time and save about $310 million, Dave Mazur, Northrop’s vice president and B-2 program manager, said earlier this year.

An overhaul takes approximately 13 months at Air Force Plant 42 in Palmdale, Calif., and includes a complete restoration of the airframe, inspections and service of the electrical and mechanical systems. A major issue with the B-2 is its low-observable coating system that contributes to its stealth characteristics, but accounts for about 70 percent of the programmed depot maintenance tasks and 30 percent of the nonmission-capable rate for maintenance down time on the aircraft, said Maj. Michael Bradley with Global Strike Command’s B-2 weapons system team.

“The B-2 has to be more complex to meet our need to penetrate defended airspace,” Bradley said. “Sustaining the B-2’s [low-observable] properties and advanced avionics, compounded by the dynamics of managing a small fleet, do lead to a lower MC rate. However, the B-2 has shown in [recent missions] it is able to surge as needed to bring significant payload and range to any fight.”

The B-1 fleet, which unlike the B-52 and B-2, no longer has a nuclear role, reported a 57.9 percent mission-capable rate, up from 43.8 percent in 2010 but still far below that of the Stratofortress.

A rise for the Global Hawk

One of the biggest jumps in mission-capable rates is in an airframe that the Air Force has been targeting for retirement: the RQ-4 Global Hawk. In 2013, the large, remotely piloted aircraft is flying at a capable rate of 74.1 percent. While that number is lower than for other drones, with the Predator at 93.4 percent and the Reaper at 91.1 percent, it is up about 20 percentage points from fiscal 2011.

The numbers are the result of a maturing fleet that has seen a specific focus on improved reliability, Grant said.

While the Air Force’s statistics do not differentiate by variant, the Block 30 version of the Global Hawk has been repeatedly targeted for retirement in Air Force budget proposals. The service flies 18 of the variants, but has said the Cold War-era U-2 manned aircraft can fly the same intelligence, surveillance and reconnaissance mission cheaper than the 3-year-old Global Hawks. The U-2 is flying at an 80.9 percent mission-capable rate in 2013.

On Sept. 5, the total Global Hawk fleet marked 100,000 flight hours, with 85 percent of that time logged by the Air Force’s fleet, according to the service. Northrop Grumman said last summer that it is working on an adapter to allow the Global Hawk to carry the same sensor payload as the U-2 to put the drone on par with the Dragon Lady.

Trainers hurting

One fleet that has seen a large drop in mission-capable rates is one where pilots and maintainers get their start in the service: trainers.

The new, propeller-driven T-6A Texan II has seen one of the biggest drop-offs in recent years, down to 63.3 percent in 2013.

The T-6 began flying as the Air Force’s primary plane in joint primary pilot training in 2003, with the service now flying 445 of the single-engine, two-seat planes. In 2010, the plane was flying at a mission-capable rate of almost 81 percent.

The T-38C Talon has also seen a drop in recent years, down to 66.3 percent in 2013, compared with 76.2 percent in 2011. The jet, which is used for advanced training for fighter and bomber pilots, has been flying for more than 46 years and the Air Force has been working to replace it, but funding has been delayed.

Air Force officials have said that a replacement to the T-38 is required by the mid-2020s, and the drop in mission-capable rates illustrates the need for the program to move forward or find other alternatives, said Richard Aboulafia, an analyst with the Teal Group.

“When you have readiness rates like this, you might be able to pull [training] off if you’ve got a large force of other aircraft that can do the job,” he said. “Some advanced training can be handed over, but not a lot. It’s beginning to take its toll.”

The Air Force upgraded the avionics on 448 of the jets beginning in 2001.

“Things would be a lot worse if the cockpits had not been upgraded,” Aboulafia said.

AIRCRAFT ASSETS & AVAILABILITY

The Air Force’s inventory of aircraft and the percentage of time the aircraft were available, known as mission-capable rates, for the past five years. *

Aircraft

Total

Avg. age

’09

’10

’11

’12

’13

A-10C

326

32.3

69.8

69.0

71.6

74.1

75.2

AC-130H

8

43.9

74.1

73.6

78.2

79.4

72.2

AC-130U

17

22.6

75.1

83.2

81.7

81.4

82.0

AC-130W**

12

24.2

77.5

80.6

85.5

82.2

82.0

AT-38B

6

50.0

81.0

72.2

73.4

82.7

85.4

B-1B

63

26.0

45.4

43.8

53.2

56.8

57.9

B-2A

20

19.1

51.3

54.9

49.2

51.3

46.7

B-52H

76

51.7

71.3

74.6

76.8

78.3

75.3

C-5A

31

42.0

45.0

52.7

55.2

63.9

67.2

C-5B

27

25.5

61.4

59.6

65.3

69.5

70.4

C-5C

2

43.2

62.0

55.1

48.0

65.2

75.6

C-5M

11

27.7

54.3

61.9

53.8

58.9

60.8

C-12C

16

37.1

N/A

N/A

N/A

N/A

N/A

Aircraft

Total

Ave. age

’09

’10

’11

’12

’13

C-12D

6

29.3

N/A

N/A

N/A

N/A

N/A

C-12F

2

29.2

N/A

N/A

N/A

N/A

N/A

C-12J

4

25.6

N/A

N/A

N/A

N/A

N/A

C-17A

221

10.0

84.6

84.4

85.9

86.8

87.0

C-20B

5

26.3

88.5

85.5

86.8

87.4

85.2

C-20C

3

26.3

97.4

97.3

N/A

97.2

99.3

C-20H

2

18.4

N/A

N/A

N/A

N/A

N/A

C-21A

46

28.5

90.5

90.4

88.7

86.5

89.9

C-27J

6

1.5

N/A

N/A

N/A

94.2

81.1

C-32A

4

14.9

93.5

92.9

93.8

91.5

91.0

C-32B

2

10.2

N/A

N/A

N/A

N/A

N/A

C-37A

9

12.7

95.9

96.0

97.7

97.9

96.9

C-37B

3

3.6

94.6

94.4

94.1

95.1

92.9

C-38A

2

15.4

65.5

65.7

50.2

73.8

75.5

C-40B

4

9.6

96.5

95.2

96.8

96.4

94.8

C-40C

7

7.3

97.0

95.5

95.5

96.5

93.0

C-130E

5

50.0

72.2

76.7

76.9

82.8

95.1

C-130H

262

25.9

71.9

73.9

73.9

75.8

75.3

Aircraft

Total

Ave. age

’09

’10

’11

’12

’13

C-130J

96

5.9

78.3

82.3

80.9

81.6

81.1

CV-22B

35

3.1

50.1

54.3

57.8

61.8

61.3

E-3B

22

35.1

79.4

71.2

70.1

72.5

75.6

E-3C

5

30.6

78.0

72.7

74.0

73.3

78.3

E-3G

4

31.2

N/A

N/A

N/A

85.4

87.9

E-4B

4

39.3

79.4

84.6

80.6

71.7

77.2

E-8C

16

12.7

78.2

81.1

77.3

78.0

74.0

EC-130H

14

40.2

76.4

70.6

71.7

76.0

76.4

EC-130J

7

13.2

72.6

65.2

66.5

62.9

64.9

F-15C

214

29.4

71.4

71.1

65.4

69.5

73.1

F-15D

35

29.9

80.4

77.4

68.1

70.6

74.1

F-15E

219

21.4

75.7

72.5

72.3

76.1

79.3

F-16C

840

22.8

75.0

75.5

74.1

73.4

74.5

F-16D

161

23.4

75.6

74.8

73.8

72.8

71.0

F-22A

186

5.9

62.9

60.9

62.7

69.1

69.1

F-35A

23

0.9

N/A

N/A

N/A

N/A

N/A

HC-130J

11

1.0

N/A

N/A

N/A

92.1

88.2

HC-130N

9

27.6

71.7

67.4

65.0

65.8

62.1

Aircraft

Total

Ave. age

’09

’10

’11

’12

’13

HC-130P

20

47.8

69.7

71.2

69.3

72.2

73.3

HH-60G

99

23.2

76.7

75.4

75.8

75.6

77.0

HH-60U

3

2.3

N/A

N/A

N/A

N/A

N/A

KC-10A

59

28.6

78.1

74.8

79.3

84.6

87.1

KC-135R

349

51.8

80.2

81.1

79.5

80.4

79.3

KC-135T

54

53.5

79.7

80.4

80.2

82.4

80.3

LC-130H

10

28.0

48.9

53.5

48.1

56.5

50.3

MC-12W

42

5.1

81.4

87.3

90.9

92.6

88.1

MC-130H

20

25.1

73.2

73.2

74.6

74.1

77.7

MC-130J

14

1.4

N/A

N/A

N/A

88.7

90.8

MC-130P

21

45.6

68.6

71.7

71.5

71.6

77.2

MQ-1B

154

6.4

93.4

93.0

93.4

93.8

93.4

MQ-9A

115

3.1

91.8

90.3

89.5

90.6

91.1

NC-135W

1

51.4

N/A

N/A

N/A

N/A

N/A

OC-135B

2

51.3

80.4

72.6

64.6

79.9

76.8

RC-26B

11

19.3

N/A

N/A

N/A

N/A

N/A

RC-135S

3

51.4

90.2

88.9

83.9

86.5

73.4

RC-135U

2

48.6

93.5

81.9

86.5

83.6

85.4

Aircraft

Total

Ave. age

’09

’10

’11

’12

’13

RC-135V

8

48.8

84.4

79.1

77.7

75.0

74.7

RC-135W

9

51.2

82.1

79.6

77.4

79.8

78.9

RQ-4B

29

3.0

N/A

55.3

55.2

69.2

74.1

T-1A

178

18.8

83.5

79.7

81.2

79.7

80.6

T-6A

445

7.9

80.8

80.3

81.0

72.8

63.3

T-38A

54

46.8

83.8

80.4

82.8

82.6

78.1

T-38C

448

46.1

77.8

76.2

72.7

68.3

66.3

T-41D

4

44.0

N/A

N/A

N/A

N/A

N/A

T-51A

3

8.1

N/A

N/A

N/A

N/A

N/A

T-53A

25

1.6

N/A

N/A

N/A

N/A

N/A

TC-130H

1

47.9

N/A

65.6

59.6

70.7

74.0

TC-135W

3

51.2

79.9

72.8

69.5

76.9

73.3

TE-8A

1

22.6

86.0

80.7

81.7

N/A

N/A

TG-10C

3

11.1

N/A

N/A

N/A

N/A

N/A

TG-10D

4

10.9

N/A

N/A

N/A

N/A

N/A

TG-14A

4

10.5

N/A

N/A

N/A

N/A

N/A

TG-15A

2

9.7

N/A

N/A

N/A

N/A

N/A

TG-15B

3

9.7

N/A

N/A

N/A

N/A

N/A

Aircraft

Total

Ave. age

’09

’10

’11

’12

’13

TG-16A

19

1.6

N/A

N/A

N/A

N/A

N/A

TH-1H

25

36.3

51.5

69.2

61.9

67.2

56.9

TU-2S

5

29.3

83.6

81.7

83.3

77.8

81.6

U-2S

27

30.6

78.3

81.1

81.6

79.1

80.9

UH-1N

62

40.6

85.1

84.1

82.1

84.9

84.9

UV-18B

3

29.4

N/A

N/A

N/A

N/A

N/A

VC-25A

2

22.9

98.1

97.9

96.4

95.6

91.9

WC-130H

9

47.7

54.6

73.0

57.0

68.2

55.3

WC-130J

10

12.4

68.3

83.5

81.4

78.9

79.9

WC-135C

1

49.2

78.0

74.0

58.4

85.6

80.0

WC-135W

1

51.3

73.0

74.8

63.1

55.7

84.2

Total/average

5,476

26.1

75.8

75.9

75.4

77.9

77.8

* Rates for 2013 are through Aug. 13. N/A indicates rate data is not available because aircraft were not in inventory for that period or data was not collected for that aircraft.